The present invention relates to a process for preparing trifluoroarylaluminum etherate compounds, especially tris(pentafluorophenyl)aluminum etherate compounds that are useful as catalyst activators for olefin polymerizations or in the synthesis of such activators. The process is particularly beneficially employed to prepare such compounds in improved isolated yields and reduced process complexity.
In U.S. Pat. No. 5,602,269, an improved method for preparing nonetherate containing complexes of fluoroaryl derivatives of aluminum, gallium or indium was disclosed. The process involved an exchange of the corresponding metal trialkyl with a fluoroaryl boron compound carried out in a hydrocarbon solvent in order to obtain the complex in its pure form without coordinated ether molecules. However, such non-coordinated aluminum complexes are known to be shock sensitive and difficult to handle.
Techniques for preparing triarylaluminum etherate compounds involve the use of Grignard reagents, as illustrated by U.S. Pat. No. 2,960,516, Australian Journal of Chemistry, vol.16, pages 794-800 (1963), DE-A 1,057,600, Zeitschrift fur Naturforschung, vol. 20b, page 5, (1965), and Journal of the Chemical Society, (1967), page 2185.